|Greater China, Singapore, Malaysia|
The Sinitic languages,[a] often synonymous with "Chinese languages", constitute the major branch of the Sino-Tibetan language family. It is frequently proposed that there is a primary split between the Sinitic languages and the rest of the family (the Tibeto-Burman languages), but this view is rejected by an increasing number of researchers. The Bai languages, whose classification is difficult, may be an offshoot of Old Chinese and thus Sinitic; otherwise Sinitic is defined only by the many varieties of Chinese, and usage of the term "Sinitic" may reflect the linguistic view that Chinese constitutes a family of distinct languages, rather than variants of a single language.[b]
Dialectologist Jerry Norman estimated that there are hundreds of mutually unintelligible Sinitic languages. They form a dialect continuum in which differences generally become more pronounced as distances increase, though there are also some sharp boundaries.
There are additional, unclassified varieties, including:
The traditional, dialectological classification of Chinese languages is based on the evolution of the sound categories of Middle Chinese. Little comparative work has been done (the usual way of reconstructing the relationships between languages), and little is known about mutual intelligibility. Even within the dialectological classification, details are disputed, such as the establishment in the 1980s of three new top-level groups: Huizhou, Jin and Pinghua, despite the fact that Pinghua is itself a pair of languages and Huizhou may be half a dozen.
Like Bai, the Min languages are commonly thought to have split off directly from Old Chinese. The evidence for this split is that all Sinitic languages apart from the Min group can be fit into the structure of the Qieyun, a 7th-century rime dictionary. However, this view is not universally accepted.
Jerry Norman classified the traditional seven dialect groups into three larger groups: Northern (Mandarin), Central (Wu, Gan, and Xiang) and Southern (Hakka, Yue, and Min). He argued that the Southern Group is derived from a standard used in the Yangtze valley during the Han dynasty (206 BC - 220 AD), which he called Old Southern Chinese, while the Central group was transitional between the Northern and Southern groups. Some dialect boundaries, such as between Wu and Min, are particularly abrupt, while others, such as between Mandarin and Xiang or between Min and Hakka, are much less clearly defined.
Scholars account for the transitional nature of the central varieties in terms of wave models. Iwata argues that innovations have been transmitted from the north across the Huai River to the Lower Yangtze Mandarin area and from there southeast to the Wu area and westwards along the Yangtze River valley and thence to southwestern areas, leaving the hills of the southeast largely untouched.
A 2007 study compared fifteen major urban dialects on the objective criteria of lexical similarity and regularity of sound correspondences, and subjective criteria of intelligibility and similarity. Most of these criteria show a top-level split with Northern, New Xiang, and Gan in one group and Min (samples at Fuzhou, Xiamen, Chaozhou), Hakka, and Yue in the other group. The exception was phonological regularity, where the one Gan dialect (Nanchang Gan) was in the Southern group and very close to Meixian Hakka, and the deepest phonological difference was between Wenzhounese (the southernmost Wu dialect) and all other dialects.
The study did not find clear splits within the Northern and Central areas:
The two Wu dialects occupied an intermediate position, closer to the Northern/New Xiang/Gan group in lexical similarity and strongly closer in subjective intelligibility but closer to Min/Hakka/Yue in phonological regularity and subjective similarity, except that Wenzhou was farthest from all other dialects in phonological regularity. The two Wu dialects were close to each other in lexical similarity and subjective similarity but not in mutual intelligibility, where Suzhou was actually closer to Northern/Xiang/Gan than to Wenzhou.
In the Southern subgroup, Hakka and Yue grouped closely together on the three lexical and subjective measures but not in phonological regularity. The Min dialects showed high divergence, with Min Fuzhou (Eastern Min) grouped only weakly with the Southern Min dialects of Xiamen and Chaozhou on the two objective criteria and was actually slightly closer to Hakka and Yue on the subjective criteria.